Invalid Token

When a user logs out from my website, they get an error that states "Invalid Token". This is a basic installation (I used used the hotstart) for Joomla 2.5.4 and then upgraded to 2.5.8

If I change the theme to the Joomla default (beez2 or atomic) the logout works correctly.

How can I fix this error?

Copy (Overwrite):

\templates\hot_sportal\html\mod_login\default.php

with

\modules\mod_login\tmpl\default.php

I have the same problem, but this solution isn't working.

ok i solved it out. I replaced the wrong file.

another problem I have now with the login is that when a user tries to login and fails, the system returns an error 500 page

How do you mean that only if user enters false username.password or every time someone tries to login???